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Measuring Matter/Transcript
Transcript Text reads: The Mysteries of Life with Tim and Moby Tim is in a classroom, trying to solve a Rubik's cube. He is not doing well. He frowns. TIM: Can't... solve... cube puzzle. He becomes more frustrated. TIM: Getting angry. Whoa-- Moby walks up to Tim, takes the cube away from him, and solves it almost immediately. He hands it back to Tim. TIM: Uh, thank you. MOBY: Beep. Tim reads from a typed letter. TIM: Dear Tim and Moby, what are mass, volume, and density? And why are they important? Love, Kira. Mass, volume, and density are all physical properties of matter. Matter is anything in the universe that takes up space. It makes up everything that you can see, feel, taste, or touch! An animation shows a sheep standing next to a tree in a grassy field. A pickup truck drives by. It keeps moving and passes a large city. Above the city, the Sun shines brightly. All of these are examples of matter. TIM: And mass, volume, and density are measurements that we can take of material objects. MOBY: Beep. TIM: Why do we measure stuff? Well, basically, to understand it better and to compare it to other stuff. For example, we measure time in hours, minutes, and seconds. An animation shows a wall clock with its hands spinning rapidly. TIM: Can you imagine if we had no way of measuring time? The clock's hands and numbers disappear, leaving it blank. TIM: We wouldn't know when to go to school, when to come home, when the next episode of Battlestar Galactica was on. Three images show a young woman in various states of confusion. TIM: And if we couldn't measure the mass, volume, and density of objects, we'd be just as confused about what they are and why they act the way they do. MOBY: Beep. TIM: Right! Measurements also help us standardize stuff. In the science lab, we use the metric system for all our measurements. Its basic units are the meter for length, the liter for volume, and the gram for mass. An image shows a metric measuring stick, a metric measuring cup, and a metric scale. The measuring stick measures meters, the measuring cup measures liters, and the scale measures grams. TIM: Because the metric system is used all over the world, scientists everywhere can compare their discoveries and ideas without too much confusion. An animation shows a world map. Images show two scientists in different parts of the world communicating with each other using metric measurements. TIM: Now, let's measure this cube. Tim holds up the Rubik's cube that Moby has solved. TIM: We'll start with its mass. Mass is a measurement of how much matter an object contains. In a lab, we measure it with a balance or a scale. Tim puts the Rubik's cube on a scale. TIM: Let's see. The cube's mass is about 250 grams. The scale's dial reads two hundred fifty grams. MOBY: Beep. TIM: Well, weight is different from mass! Weight is actually a measure of the effect gravity has on an object. And it's measured in Newtons, not in grams. For example, on Earth, this cube weighs 2.5 Newtons. An animation shows a view of Earth from space, along with a Rubik's cube on a scale. The scale's digital screen reads: 2.5 Newtons. TIM: But on the Moon, where the gravity is only one-sixth as strong as Earth's gravity, the cube only weighs one-sixth as much! A second animation shows the Moon from space, along with a Rubik's cube on a scale. The scale's digital screen reads.41667 Newtons. TIM: No matter where it is, though, the cube's mass is always the same, 250 grams. Now, to volume. The cube's volume is a measure of how much space it takes up. An animation shows only an outline of the Rubik's cube, illustrating its volume. TIM: Since this object is a solid, the volume is measured in cubic centimeters. The image of the Rubik's cube fills in, returning it to its ordinary appearance. TIM: And you can calculate it by multiplying its length, by its width, by its height. Graphics illustrate the dimensions of the cube. Text reads: 10 cm times 10 cm times 10 cm equals 1,000 cubic cm. MOBY: Beep. Moby holds a glass of water. TIM: Well, liquid volume is measured in liters. One milliliter takes up the same amount of space as one cubic centimeter. With an eyedropper, Tim squeezes a milliliter of water into a cube-shaped container one cubic centimeter in volume. TIM: And while it's easy to measure the volume of a cube, it's a little more difficult with an irregularly shaped object like this pebble. Tim holds up a large pebble. TIM: Matter displaces liquid. That's a fancy way of saying it takes up space. Tim drops the pebble into a measuring cup of water. TIM: If you can measure the amount of liquid that the object displaced, then you've found the volume of the object! Before we dropped this rock into it, the water had a volume of 50 milliliters. An animation shows a clear measuring cup containing 50 milliliters of water. Tim drops his rock into the cup. TIM: After we dropped it in, the water level rose to 70 milliliters! The measuring cup now reads 70 milliliters of contents. TIM: So we know that the pebble has a volume of 20 milliliters, or 20 cubic centimeters, since it's a solid. A graphic next to the measuring cup indicates the 20 milliliter difference that Tim describes. MOBY: Beep. TIM: Ah, density. Density measures how heavy something is for its size. Tim's Rubik's cube is placed next to a solid gray cube of the same size. TIM: Are its atoms packed close together, or far apart? An animation represents the atoms in both the Rubik's cube and the gray cube. The atoms in the gray cube are closer together than the atoms in the Rubik's cube. TIM: We can calculate density by dividing an object's mass by its volume. Tim writes the equation for density on a blackboard. It reads, D equals M over V. TIM: Let's see. The mass was 250 grams, and the volume was 1,000 cubic centimeters. Tim writes text on the blackboard that reads: 250 grams over 1,000 cubic centimeters. TIM: 250 over 1,000 is 0.25. Text on the blackboard now reads: 250 grams over 1,000 cubic centimeters equals 0.25 grams per cubic centimeter. TIM: So the density of this cube is 0.25 grams per cubic centimeter! Pretty impressive, huh? MOBY: Beep. Moby picks up the Rubik's cube. He rapidly twists it into several different configurations, stopping to show Tim each of them. TIM: OK, now you're just showing off. Category:BrainPOP Transcripts Category:BrainPOP Science Transcripts